Risk of loosing vehicle

I got a loan against my vehicle so my daughter and granson and i could have a place to live. The payment i did not realize of 400 a month is just interest not toward the loan itself. So the 1200 i made so far..none of it went towards the loan Dumb me i know, should have read fine print, but did what we had to do to move, Now we dont have the extra to pay the actual loan. I cant loose my vehicle. Please this is hard for me to do but no other option. Thank you